Plumbing, Water Heaters

Symptoms of Bad Water Heater Dip Tube

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The water heater is one of life’s greatest inventions. It is the heart of your home – pumping hot water throughout your home, enabling you to keep your family clean and healthy. When the water heater doesn’t work correctly, it disrupts every action of our daily lives.

If your water heater is showing signs of distress, before you go and buy a new one, this article will help you determine if a simple part is all that is neededFour symptoms of a bad water heater dip tube are:

  1. White, egg shell-type flecks of plastic in the water
  2. Pockets of cold water mixed in with the hot water
  3. Hot water quickly cools
  4. Hot water is only luke-warm 

If you notice one or more of the above symptoms, there is no need to panic. A bad dip tube does not mean you need to replace your entire water heater. Immediate attention is required, though. This article will explain what a dip tube is, the crucial role it plays in your water heater, and what to do if it needs to replace your dip tube.

What Does a Water Heater Dip Tube Do?

A dip tube is a plastic tube that connects to the cold water inlet on top of the water heater. The tube carries the cold water down to the bottom of the tank, where the burner is. Once the water is heated, it naturally rises to the surface and is pulled out of the hot water outlet and into your shower, sink, or other appliance. 

Hot water is already setting at the top of the tank. The tube itself prevents the cold water from cooling the already heated water. The dip tube forces cold water to the bottom of the tank, where it is heated and then rises to the top of the tank. 

This wait time is one reason why some homeowners have chosen to replace their tank water heaters with tankless water heaters. Hot water is ready on demand, and it requires less energy and time to heat, saving money and the environment.  

Do All Water Heaters Have Dip Tubes?

As a general rule, electric and gas water heaters have a dip tube. The dip tube connects to the cold water inlet, located at the top of the tank, and stops 6 to 8 inches from the bottom. If the cold water outlet is on the side or bottom of the tank, a dip tube is unnecessary because cold water is already supplied to the bottom of the tank. 

If your water heater does not have a dip tube, there are other possibilities as to why your water is not staying hot or is not heating at all.

  • The thermostat could be malfunctioning.
  • There is a buildup of sediment on the bottom of the tank, preventing the heating element from working properly.
  • The water heater is not able to keep up with the demands placed on it.

 In any of these instances, it would be best to contact a licensed professional to diagnose the issue and advise you on how to correct the problem. 

How Long Do Dip Tubes Last?

Dip tubes can last the life span of the water heater. The age of the water heater and the water pH can also affect the life span. However, water heaters built in the early to mid-’90s were supplied with faulty dip tubes from a major supplier. If your water heater was manufactured during these years, it would be wise to replace the dip tube immediately, even if you are not experiencing any issues.

Dip tubes are made of plastic. When plastic is continually underwater, exposed to changing water temperatures and the acidity of water, it will begin to break down. Yes, the water is acidic. The more familiar term is hard water. Do you have water spots on your wine glasses? Does your showerhead have a white buildup? These are signs of hard or acidic water. 

The water heater, or, more specifically, the dip tube, takes the brunt of this buildup. Over time, the wear-and-tear of use and hard water can cause the plastic dip tube to break down. If you notice pieces of plastic in your drain, this is a sure-tell sign the dip tube is breaking down and requires immediate attention.

Another sign the dip tube is starting to break down is if you notice your water starts out hot and then goes cold. This temperature change is due to cold water leaking out of the drip tube before making it to the bottom of the tank and warming.

If your water never gets hot or you have no hot water, the dip tube could be broken, or it has disintegrated. The cold water is coming out of the cold water inlet and going directly into the hot water outlet and out the faucet, never having a chance to heat up. 

How Much Does It Cost To Replace a Water Heater Dip Tube?

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Water heater dip tubes range in price from $7 to $40. If you choose to hire a professional to do the work, the average cost is $150. While saving money is a high priority, working with water heaters can be dangerous, especially if you don’t have any training. A professional will know how to safely operate the water heater and remove the damaged dip tube.

You need to flush sediment buildup from a bad dip tube from the system. A professional will be able to perform the maintenance required to do this safely.

If the dip tube has disintegrated, causing pieces of the plastic tube to come through the plumbing system, this can clog filter screens and aerators of the faucet or appliance that uses hot water. Again, this is something a professional will be able to do safely.

Where To Buy a Water Heater Dip Tube?

You can find dip tubes at your local hardware store or online. If you are unsure what size of dip tube your water heater uses, you can go to the manufacturer’s website and get specifications for your water heater. 

Before you roll up your sleeves and start taking the water heater apart, keep in mind that not all dip tubes are the same. Some dip tubes are straight rods of plastic. Others have a curved bottom. They also come in different sizes, depending on the type of water heater you have. 

Depending on the type and age of your water heater, replacing the dip tube may not be a simple process. In addition to disconnecting the cold water supply and draining 5 to 10 gallons of water out of the water heater, if your water heater has copper tubing, this will require a measure of cutting and soldering. This in itself presents safety hazards. 

Also, keep in mind that you could void the warranty by doing any work yourself, depending on which water heater you have. Some companies, such as Bradford White, are very particular about their water heaters being serviced only by an authorized technician.

Be sure to read the fine print of your warranty to find out. If you are not sure, you can always check the warranty status and requirements online. 

Final Thoughts

While any issue with a water heater can be stressful, being observant of signs that your water is in distress will prevent much more extensive – and expensive – damage down the road. And while it is tempting to do the work yourself, some things are best left to the professionals.



Hubert Miles | Licensed Home Inspector, CMI, CPI

Hubert Miles is a licensed home inspector (RBI# 2556) with more than two decades of experience in inspection and construction. Since 2008, he has been serving South Carolina through his company, Patriot Home Inspections LLC. As a Certified Master Inspector, Hubert is dedicated to providing his expertise in home inspections, repairs, maintenance, and DIY projects.